The History of Champions league

Tournament was inaugurated in 1955, at the suggestion of the French sports journalist and editor of Gabriel Hanot, as a continental competition for winners of the European national football leagues, as the European Champion Clubs' Cup, abbreviated to European Cup.
The competition began as the 1955–56 using a two-leg knockout format where the teams would play two matches, one at home and one away, and the team with the highest overall score qualifying for the next round of the competition. Until 1992, entry was restricted to the teams that won their national league championships, plus the current European Cup holder. In the 1992–93 season, the format was changed to include a group stage and the tournament was renamed the UEFA Champions League. There have since been numerous changes to eligibility for the competition, the number of qualifying rounds and the group structure. In 1997–98, eligibility was expanded to include the runners-up from some countries according to UEFA’S coefficient ranking list. The qualification system has been restructured so that national champions from lower ranked countries have to take part in one or more qualifying rounds before the group stages, while runners-up from higher ranked countries enter in later rounds. Up to four clubs from the top-ranked countries are currently given entry to the competition.
Between 1960 and 2004, the winner of the tournament qualified for the now defunct Intercontinental Cup against the winner of the Copa libertadores of South America. Since then, the winner automatically qualifies for the FIFA organized Club World Cup with other winners of continental club championships.
Stages
The tournament consists of several stages and begins with three preliminary knockout qualifying rounds. Different teams start in different rounds, according to their position in domestic league and the UEFA coefficients of their league, while the sixteen top ranked teams spread across the biggest domestic leagues qualify directly. The current system was adopted in 2003.
A change of the format will be carried out from session 2009-10 onwards. The main focus of the changes was to enable champions coming from associations ranked 13 to 53 access to the main tournament more easily through a separate qualifying route, rather than going head-to-head with non-champions from associations ranked 1 to 12. Five teams will enter into the group stage from each new route.
22 teams will then directly qualify for the group stage, compared to only 16 teams in the old system. The additional 6 directly qualified teams are the champions of associations ranked 10 to 12, and the 3rd placed teams in associations ranked 1 to 3.